In many industrial, commercial, and scientific applications, multiple devices operate in a coordinated manner. For example, to create immersive virtual-reality experience, multiple cameras need to collaborate to capture 360 degree panoramic images. An important issue is how to make the shutter in each camera work simultaneously, i.e., synchronizing video capturing at frame level or even frame line level.
FIG. 1 is a schematic diagram illustrating a multi-camera system for capturing images. Referring to FIG. 1, for example, two 4k cameras, i.e., cameras capable of shooting images with a horizontal resolution of about 4,000 pixels, may be aligned to shoot a moving car. Each camera has a field of view that covers a portion of the space to be imaged. Video frames generated respectively by the two cameras may be combined to create the virtual-reality experience. In one possible setup of the multi-camera system, each pixel of the video frame may correspond to a 1-cm distance on the car's moving path. If the car is moving at a speed of 2 cm/ms, then the car passes 2 pixels in 1 ms. Thus, if the shutter operation of one camera lags behind the other camera by 1 ms, the car's position will have about a 2-pixel difference on the two video frames generated by the two cameras respectively. Such pixel difference is usually called the “ghosting” artifact.
The disclosed methods and systems address one or more of the problems listed above.